The following is not an admission that anything discussed herein is citable as prior art or part of the common general knowledge of persons skilled in the art.
International (WIPO) publications WO/2001/066474, WO/2004/071973, WO/2005/016498, WO/2005/016826 and WO/2006/015496 describe various membrane supported biofilm devices or processes. These publications are incorporated herein in their entirety by this reference to them. These documents describe various apparatus or process details that may be useful in working with a membrane supported biofilm, although statements in these publications or in U.S. Application Ser. No. 60/913,195 do not limit or define the claims of this patent.
International publication number WO/20018066174 describes an apparatus to transfer gas to or from a liquid having a flexible and oxygen permeable but liquid water impermeable membrane, a flexible and gas permeable spacer, an inlet conduit, an outlet conduit and a non-rigid restraint system. When used for treating wastewater, an aerobic biofilm is cultured adjacent the planar elements, an anoxic biofilm is cultivated adjacent the aerobic biofilm and the wastewater is maintained in an anaerobic state. A first reactor for treating wastewater has an anaerobic section, a plurality of gas transfer membrane modules, and an aerobic section. A biofilm is cultivated on the surface of the gas transfer membranes in fluid communication with the anaerobic section. Biological reduction of COD, BOD, nitrogen and phosphorus are achieved. In a second reactor, phosphorus is also removed chemically in a precipitation branch.
International publication number WO/2004/071973 describes a membrane supported biofilm reactor with modules having fine, hollow fibres, for example, made from dense wall Poly methylpentene (PMP) used in tows or formed into a fabric. In one module, one or more sheets of the fabric are potted into a module to enable oxygen containing gas to be supplied to the lumens of the hollow fibres. Various reactors and processes, for example to treat wastewater, using such modules are described. Mechanical, chemical and biological methods are used to control the thickness of the biofilm.
International publication number WO/2005/016498 describes a membrane module apparatus to transfer a gas to or from a liquid having a sheet with at least one gas transfer surface. The gas transfer surface is in flow communication with a header through a gas channel. The module may be used to support a biofilm on the gas transfer surface. A plurality of sheets or portions of sheets may be separated by spacers.
International publication number WO/2005/016826 describes a membrane supported biofilm reactor with modules having fine, hollow fibres, for example, made from melt spun thermoplastic polymers treated after spinning to increase their permeability to oxygen, used, for example, in tows or formed into a fabric. In one module, one or more sheets of the fabric are potted into a module to enable oxygen containing gas to be supplied to the lumens of the hollow fibres. Various reactors and processes, for example to treat wastewater, using such modules are described. In one process, oxygen travels through fibers, optionally through an attached biofilm, to oxygenate surrounding water. Mechanical, chemical and biological methods, for example endogenous respiration, are used to control the thickness of the biofilm.
International publication number WO/2006/015496 describes a module with hollow gas transfer fibers arranged in tows and potted into a module. The module may be used to treat wastewater by supplying hydrogen containing gas via the interior of the fibers to a biofilm present on an exterior surface of the fibers.